TiLite ZR Footplate Light - Harmanie Light

Introducing the Harmanie light! This project was inspired by my best friend Harmanie, thus the name. We were walking down a sidewalk in Vancouver at night and I saw that in the spaces between street lights the sidewalk was occasionally very dark and made it hard for us to see obstacles. It occurred to me that she could really benefit from a flashlight that would always be with her chair. Harmanie is a disabled dance artist who dances in her chair so the light needed to be sleek and nearly hidden so she wouldn't have to remove it for performances. She also had an open footplate design so I decided I could hide a battery between the tubes, put led's along the bottom, and also give her a solid surface for her feet. And Harmanie loves gold.

Files can be downloaded on Thingiverse:

https://www.thingiverse.com/thing:5162785

Start printing, or order the completed prints from a reputable online service, or get a friend to print them.

Install the led's, switch, resistors, and solder them up. Sorry, but this is going to be a bit vague. I don't have step by step detailed photos as I was not intending to release this as an instructable. Essentially, you will place all 10 LED's into the footplate with the same orientation to the leads. I put all the + or long leads at the top and all the ground leads at the bottom and glued them in place with a dab of hot glue. Then I bent the ground leads over one on top of each other to form a continuous wire and soldered them all together to give 1 ground connection. On the top I soldered resistors to each led cutting the leads short so they could be fit in a small space. Then I used the lead of each resistor I had left long to also create another wire running off to the left. We will connect power and ground to these leds which are now wired in parallel with a series resistor on each led. The resistor value is not too critical. Looks like I used 200 ohm on these if im reading the bands right. Anywhere from 150 ohm to 215 should be good.

The switch is salvaged from a very common dollar store aluminum led flashlight. The type with a click button on the removable end cap where you install the batteries. The switch has a rubber pad which allows for a very sleek look to the bottom of the plate and made it easy for Harmanie, who is left handed to reach down below and switch it on or off.

Your power connections are going to be run in series from the power bank, through the switch, through the led's, and back into the power bank. In order to have the battery replaceable I chopped off a USB power cable and connected to the red and black wires. Red is positive, black is ground.

You need to permanently install the USB charging cable as well at this time or else you will need to disassemble the footplate to charge it which is hardly convenient.

VERY IMPORTANT!!! Almost all USB power banks have a built in low current shut off. This means if your led's don't draw enough current the power bank will shut off power after 30 seconds or so and you will have to switch it off and then back on again to bring back the light. I had to add 2 more LED's to this circuit to draw enough current to keep the circuit active. They ended up being hidden inside, also in parallel with the other led's. Test your circuit before you apply hot glue in case you need to make revisions.

Last step, apply hot glue! We are using this to seal the circuit and help protect the electronics. Also helps to prevent accidental shorts on the led's

Test it out!

Again, most important, if it turns on successfully, make sure it doesnt turn off after 30 to 60 seconds due to insufficient current draw. If it goes past 1 minute running you're golden!

Install it on the chair.

Final Test!

Try everything out. Including charging and deploying and stowing the charging cable. It was made to always have a cable on hand, and Harmanie has not had any problem with the cable falling out and dragging behind her. We also thought we might have to worry about moisture and dirt in the plug, but it seems to attract very little of it so it hasnt been a problem. You could put tape over the hole if youre really concerned.

visible in these pics is the switch on the top right, this is the textured rubber circle. The other button can be pressed to tell you how much battery is remaining, and if its charging, but of course not when in the chair.